General rules for bosonic bunching in multimode interferometers

TL;DR

This paper experimentally investigates bosonic bunching in multimode interferometers, confirming known and new rules that describe the behavior of up to 3 photons in 16 modes, with implications for quantum technologies.

Contribution

The study verifies the bosonic birthday paradox and introduces a new n!-factor quantum enhancement rule for bosonic bunching in multimode interferometers.

Findings

Confirmed the bosonic birthday paradox in experiments.

Discovered a new n!-factor quantum enhancement rule.

Demonstrated bosonic bunching behavior in 16-mode interferometers.

Abstract

We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.